The settings are relatively simple:1) only computers connected to the LAN (IP range 192.168.1.x) are allowed access2) external timeserver may only be queried, they can't change things here3) your server looks for 3 external timeservers4) no internet? use the internal clock (as backup)

On each workstation:Open the application to change system date & time (system-config-date) and select the option that you want to synchronise through the network. Enter the IP address of your local timeserver and you're done.